The present invention is related to disposable absorbent articles having a consumer activated component that is expandable.
Disposable absorbent articles are used to absorb and retain body exudates, such as urine, fecal material, menses, and the like. A particular desired feature of disposable absorbent articles is the capability to acquire and hold body exudates to minimize leakage of body exudates from between the absorbent article and the wearer.
References in the art teach adding a spacer to the disposable absorbent article for aiding in the containment of fecal material. Such spacers suffer from the disadvantage that they increase the initial thickness of the disposable absorbent article, and thereby increase shipping and storage costs. Such spacers may also be perceived by consumers to be uncomfortable because of their thickness prior to application of the diaper to the wearer. Examples of spacers are shown in the following references: U.S. Pat. No. 5,176,672 issued Jan. 5, 1993 to Bruemmer et al., U.S. Pat. No. 5,171,236 issued Dec. 15, 1992 to Dreier et al., and U.S. patent application Ser. No. 08/698,471, Spacers for Use in Disposable Absorbent Articles and Disposable Absorbent Articles Having Such Spacers, filed Aug. 15, 1996 by Allen et al.
Still other references disclose absorbent articles having inflatable structures. French Patent Application 2,561,078 published Sep. 20, 1985 in the name of Lefebvre discloses a diaper having a structure which is inflatable by mouth. Such inflation can be awkward or inconvenient, especially in public areas or when the diaper is already fastened to the wearer. Such an arrangement is also disadvantageous because of sanitary considerations.
U.S. Pat. Nos. 3,881,491 and 3,921,232 issued to Whyte on May 6, 1975 and Nov. 25, 1975 respectively, disclose disposable absorbent articles having self is inflating structures. The self inflating structures include a wall of semipermeable material through which body fluids can pass, and a gas evolving material which interacts with an activator material (e.g., urine) to inflate the structure. The structure taught by Whyte primarily prevents core densification and suffers from the disadvantage that it requires an activator material from an external source, such as urine. The wearer may not urinate at the desired time, in the desired location, or in the desired amount to properly inflate the structure. U.S. Pat. No. 5,876,393 issued Mar. 2, 1999 to Ahr et al. and U.S. Pat. No. 5,530,459 issued Jul. 19, 1994 to LaVon et al. disclose inflatable diaper components whose inflation requires wetting of the component or mixture of two different materials.
Accordingly, it would be desirable to provide a disposable absorbent article having a component that is expandable by a wearer, or by a person caring for the wearer, before or after the absorbent article is fastened to the wearer. It would also be desirable to provide a diaper having a spacer for maintaining a fecal void space, wherein the spacer thickness can be increased without the need for wetting of the spacer, and wherein the spacer thickness can be activated at a time selected by the consumer or wearer. Further, it would be advantageous to provide a sanitary napkin embodiment of the present invention having a component which is expandable to provide separation and lift of the topsheet and core relative to the backsheet of the sanitary napkin, and increase the caliper of the sanitary napkin along the longitudinal centerline of the sanitary napkin.
In order to solve the problems of the prior art, the present invention provides a disposable absorbent article having a topsheet, a backsheet, an absorbent core disposed intermediate the topsheet and backsheet, and an expandable component. In a preferred embodiment, the expandable component comprises a compressed resilient element disposed within an air impermeable envelope. The air impermeable envelope can be evacuated, such as by vacuum sealing, to have an internal pressure less than the outside atmospheric pressure. The expandable component expands from a first thickness to a second thickness greater than the first thickness upon opening of the air impermeable envelope.
The air impermeable envelope can comprise a port having a releasable closure. The releasable closure can be removed at the point of use of the disposable absorbent article to permit air to enter the envelope through the port, thereby providing expansion of the expandable component. In one embodiment, the releasable closure can be resealable, so that air drawn into the port does not escape when the expandable component is subjected to compressive loading.
In certain preferred embodiments of the present invention, the port may comprise a gas-permeable component such as a gas-permeable membrane or film. The rate of expansion of the expandable component may be controlled by varying the diffusion rate of the gas-permeable membrane and the port area.
The expandable component can be positioned on the body facing surface of the topsheet, on the garment facing surface of the backsheet, or between the topsheet and the backsheet. In one embodiment the expandable component is disposed intermediate the backsheet and the absorbent core. The expandable component can comprise a spacer for maintaining a fecal void space in a disposable diaper. Alternatively, the expandable component can provide a seal in the waist regions or the side margins of a disposable diaper. In another embodiment the expandable component is located along the longitudinal centerline of a sanitary napkin to provide lifting of the topsheet and core relative to the backsheet, and increased caliper of the sanitary napkin along the longitudinal centerline of the sanitary napkin.